On Synthetic Aperture Radar Azimuth and Range Resolution Equations

This paper discusses spatial resolutions for ultrawide-band-ultrawide-beam (UWB) synthetic aperture radar (SAR) in comparison to narrow-band-narrow-beam (NB) SAR. The study shows that in the intensity interval from -6 dB to 0 dB, the behavior of the impulse response function in NB SAR imaging (IRF-NSAR)-sinc function-and the impulse response function in UWB SAR imaging (IRF-USAR) in azimuth and range are similar. This similarity is utilized in a derivation of new spatial resolution equations for UWB SAR based on -3 dB width or half power beamwidth (HPBW). Signal fractional bandwidth and associated integration angle are shown to affect the behavior of IRF-USAR. The effects to HPBW are described by the so-called HPBW narrowing/broadening factors.